<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    // charAt 返回指定位置的字符
    const str = 'hello';
    console.log(str.charAt(0));

    // charCode 返回指定位置的Unicode编码
    // Unicode编码和ASCII码前128个一样
    const str1 = 'hello';
    console.log(str1.charCodeAt(0));

    // fromCharCode 根据Unicode编码返回字符
    const res = String.fromCharCode(107, 108);
    console.log(res);
</script>
</body>
</html>